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dc.contributor.authorLiang, Xiaohua.en_US
dc.date.accessioned2009-07-09T17:34:57Z
dc.date.available2009-07-09T17:34:57Z
dc.date.issued1991-07-09T17:34:57Z
dc.identifier.urihttp://hdl.handle.net/10464/1847
dc.description.abstractMedium' alkaliniiation occurred -lipon the addition of L-Glu to mechanically isolated Asparagus sprenger-i mesophyll cells suspended in 1 mM CaS04. Alkalinization resulted from the coupled entry of H+ and L-Glu anion into the cells. This H+ IL-Glu symport did not stimulate K+ efflux. K+ efflux has been observed during H~ lamino acid symport in other systems. The stimulation of K+ efflux by proton coupled symport is regarded as an indicator of a plasma membrane depolarizing electrogenic symport process. H+ IL-Glu symport in Asparagus sprengerimesophyl1 cells was investigated to determine whether or not the process was electrogenic. The rate of uptake of 0.25 11M 3H-MTPP+ ( Methyltriphenylphosphonium, methyl-3H ) is a probe for monitoring changes in the membrane potential. 3HMTPP+ uptake was reduced by K+ or CCCP, agents known to depolarize the membrane potential. Uptake of 3H-MTPP+ was also inhibited by L-Glu but not by D-Glu. Conversely, 10 mM external MTPP+ inhibited the uptake of 14C-U-LGlu. Simultaneous measurements of the rates of 14C-U-L-Glu uptake and L-Glu dependent H+ influx showed that the molar stoichiometry of H+ IL-Glu symport was 2 to 1. K+ or Na+ stimulated H+ efflux was completely inhibited by DCCD, DES, oligomycin and antimycin reagents which inhibit ATP driven H+ efflux. The H+ efflux \Vas also stimulate.d by the weak acids, butyric acid and acetic acid, which are known fo-aCidify the cytoplasm. This weak acid stimulated H+ efflux was also completely inhibited by oligomycin. It was calculated that net L-Glu dependent H+ influx increased by 100% in the presence of oligomycin and that despite net medium alkalinization H+ IL-Glu symport stimulates ATP dependent H+ efflux. 11 The data presented in this study indicate that H+ IL-Glu symport is electrogenic. The data also show that ATP dependent Ht efflux rather than K+ efflux is the- process compensating for thi~ electrogenic H+ IL-Glu symport.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectAsparagus sprengeri.en_US
dc.subjectCell membranes.en_US
dc.subjectAmino acids--Metabolism.en_US
dc.subjectCells.en_US
dc.subjectAdenosine triphosphatase.en_US
dc.subjectAsparate aminotransferase.en_US
dc.titleElectrogenic proton/L-glutamate symport in isolated asparagus sprengeri mesophyll cellen_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.nameM.Sc. Physicsen_US
dc.degree.levelMastersen_US
dc.contributor.departmentDepartment of Physicsen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US
refterms.dateFOA2021-08-07T02:00:24Z


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